Threshold photoelectrons coincidence spectroscopy of N-2(2+) CO2+ ions

Threshold photoelectrons coincidence (TPEsCO) spectra of the nitrogen and carbon monoxide dications have been recorded with improved resolution (approximate to 40 meV) allowing us to clearly resolve the lowest three vibrational progressions in each species. For the nitrogen dication we have identified, for the first time, the (3) Sigma(g)(-) slate predicted by theory and determined its constants, In the case of the CO dication, we have determined that the v = 0 level of the 1(1) Sigma(+) state is almost degenerate with X(3) Pi, v = 1 and is thus one vibrational quantum lower than previously believed.